RaPi2B & Recalbox (8.0.1) - cannot connect Bluetooth Controllers

[6kbyte]

Hi,

I hope someone can help me, I have a problem with my Raspberry Pi 2 B (v1.1) and Recallbox (v8.0.1) in combination with various USB controllers. Just fyi: I dont have any kind of Linux experience.

Hardware:
Raspberry Pi 2 B (v1.1)
Edimax BT-8500 Bluetooth 5.0 USB adapter
TP-Link TL-WN725N WLAN USB adapter
Logitech K400+ Wireless Keyboard with USB Adapter
2x Google Stadia Controller (Bluetooth enabled)
2x Microsoft XBOX Wireless Controller (v1914, purchased 2023)

Software:
Recallbox v8.0.1 for the Raspberry Pi 2 (installed with the current Raspberry Pi Imager v1.7.5)

My problem:
I am unable to pair any of the controllers listed above and basically the system behaves strangely during the pairing process. When I try to connect an input device, the status LED on the device flashes, I get a message that the connection failed while the status LED suggests it is connected - but no inputs are possible. If I delete the connection and repeat the process, the same thing happens. Sometimes I get the message "Ccnnection successful", but it still doesn't work. Even when I reboot the system, the controller shows me that it has connected, but the controller doesnt respond. Both the XBOX and the Stadia controller show the same behavior - if I connect them via cable, everything works fine and I can assign the buttons. At first I thought it might have something to do with the Bluethooth stick, but I can pair audio devices successfully and they work. If I install for example RetroPi, Lakka or Batocera, it is also not possible to connect one of the two controllers via Bluetooth, always with very strange behavior - sometimes it tells me it is connected, sometimes it tells me it is not connected, sometimes it is connected but not shown in the list of connected devices. In all cases, however, neither controller responds to any input, just like Recalbox. I've installed the operating systems several times, reset them, tried other SD cards, invested tons of time and now I'm just fed up - you guys are kind of my last hope. I would just like to understand it.

Can you please help me?

Regards,

6kbyte